MC4R and obesity due to melanocortin 4 receptor deficiency: Stratification by sex demonstrated that carrying the common MC4R rs17782313 is significantly associated with an elevated predisposition to obesity under the recessive model among females only (OR = 1.41, 95% CI: 1.09–1.82, p = 0.01), with an average of 0.85 BMI increment compared with wild type and one risk allele carriers.